A conventional anvil-type VSI rock crusher includes a plurality of anvils secured to an anvil ring in a circular configuration. A spinning rotor mounted on a vertical shaft positioned at the center of the anvil ring ejects material directed through the top of the rotor laterally through exit ports. The material ejected from the rotor impacts the anvils at extremely high velocity and shatters into smaller particle sizes.
Although anvil-type rock crushers are highly effective, the anvils experience substantial wear given the severe conditions under which they function and must be replaced regularly. The replacement operation is time consuming and expensive for the operator because replacement parts are expensive, the crusher is out of service, and a scrap fee is incurred for discarding the worn out anvils.
A conventional anvil assembly known in the prior art is shown in FIG. 1. With additional reference to FIGS. 2A and 2B, it can be seen that the anvil 1 comprises an impact body 2 connected to a mounting stob 3 via neck 4. The anvil 1 is attached to an anvil ring 5 using a slotted anchor plate 6 welded to the anvil ring. Gaps 7 between adjacent anvils 1 are blocked off using a smaller side anvil 8 secured to the anvil ring 5 with a second anchor plate 9.
When one side S1 of the anvil is fully consumed, the anvil can be pulled up, inverted, and reinstalled to expose the other side to wear. When the second side S2 of the anvil is consumed, as shown in FIG. 2C, the anvil is removed and replaced with a new one. Since the mounting stob 3 and neck 4 must be discarded along with the body 2, this results in high scrap loss and disposal expense to the end user. The scrap loss increases if the side anvil 8 must also be replaced. It will also be appreciated that the conventional anvil 1 is more expensive to manufacture because of the need to incorporate material to form the stab 3 and neck 4.